A full bunker shot travels about one third the distance of a regular shot, so when you have to clear 30 yards of sand play your normal sand shot but with a longer club
Getting more distance is usually just the process of making sure your shaft is leading into impact so practice hitting low chips, pitches and knock downs to get the correct feel for reaching impact with the correct club loft
Improve your impact by keeping your hands and body moving at the same speed, many times the body slows down for the arms and creates a hands swing where you are better off having the torso rotate and bring the arms along